"We have got to have far more bold action on criminal justice reform like having true marijuana justice, which means that we legalize it on a federal level and reinvest the profits in communities that have been disproportionately targeted by marijuana enforcement," Booker said at the CNN-hosted debate."

Booker was responding to former Vice President Joe Biden, who laid out his plan to "change the way we look at prisons."

Biden said:

Right now, we're in a situation where, when someone is convicted of a drug crime, they end up going to jail and to prison. They should be going to rehabilitation. They shouldn't be going to prison. When in prison, they should be learning to read and write and not just sit in there and learn how to be better criminals.

And when they get out of prison, they should be in a situation where they have access to everything they would have had before, including Pell grants for education, including making sure that they're able to have housing, public housing, including they have all the opportunities that were available to them because we want them to become better citizens.

That's the essence of what my plan, in detail, lays out.

Asked for his response, Booker replied:

Well, my response is that this is a crisis in our country because we have treated issues of race and poverty, mental health and addiction with locking people up and not lifting them up.

And Mr. Vice President has said that, since the 1970s, every major crime bill -- every crime bill, major and minor, has had his name on it. And, Sir, those are your words, not -- not mine.

And this is one of those instances where the house was set on fire and you claimed responsibility for those laws. And you can't just now come out with a plan to put out that fire. We have got to have far more bold action on criminal justice reform, like having true marijuana justice..."

One of the criticisms aimed at Biden by the current crop of leftist candidates is the fact that he helped write the 1994 crime bill, which some blame for mass incarceration.

Former HUD Secretary Julian Castro, also appearing in debate number two, said he agrees with Sen. Booker "that a lot of what Vice President helped author in '94 was a mistake. And he has flip-flopped on these things. And that's clear.

"But let me say," Castro continued, "when we talk about criminal justice reform, there are a lot of things that we can talk about -- sentencing reform, cash bail reform, investing in public defenders, diversion programs.

I'm proud that I'm the only candidate that has put forward a police reform plan, because we have a police system that is broken and we need to fix it. And whether it's the case of someone like Tamir Rice or Michael Brown or Eric Garner, where the Trump Justice Department just decided not to pursue challenges...we need to ensure we have a national use of force standard and that we end qualified immunity for police officers so that we can hold them accountable for using excessive force."

Summing up: Legalize marijuana at the federal level; no prison for people convicted of drug crimes; and a national use-of-force standard for police officers.